1303 Brakes

[H2OSB]

I would like to start a thread for disc brake upgrades using info from those who have real world experience or know enough to make a substantial contribution such that this thread could become a stickie.

I've been doing a lot of research today because, oddly, I still don't know for certain what brakes I want to run on my Super Beetle. I had planned to run a full 944 set up front and rear with 911 M calipers on the front to get better balance, however, I've decided fitting the 944 spindles safely (and the work thus required to do so) is more than I want to deal with in both time and money spent.

I would really like to run some version of 914 brakes on the front...at least rotors because they both bolt on out of the box, and I own a set already For the rear, I still plan to use the 944 brake apparatus because I REALLY like the 944 parking brake system, and, I have all the parts for the conversion. I have discovered the early 912 rear rotors fit over the 944 parking brake shoes in the same fashion, so I will use them with a different caliper.

After talking to Lanner Khan about this quite a bit (I'm pretty sure I drive him crazy), I am going to run front disc brake conversion brackets such as these from Topline http://toplineparts.com/brakes/disc-bra ... -0989.html with a secondary bracket to adapt radial mount Wilwood calipers over early 914 front rotors. There are a lot of detailed reasons for this based upon rotor width and other dimensions that I won't go into here. Along those same lines, I will use the same radial mount Wilwood calipers on the rear, with caliper adapters albeit with smaller pistons.

I know there are tons of folks who have successfully adapted some kind of Porsche brakes to their cars, but I am absolutely anti-bling, and want what is lightest and most effective brakes without being ultra expensive. My car will not be a show car, however, I will use it for autocrossing, so I do want a bit more stopping power than the typical Ghia front/aftermarket rear conversions provide, though not too much more is required. My engine is going to either be a 1911 or 2056 T4 conversion, so somewhere betwixt 100-130hp.

All this said, I would have loved to have some effective and clever OE type bolt on set up to get the braking power I want (i.e. the Old Euro Talbot Horizon calipers were a bolt on to Ghia (and 1302S/1303S) spindles and gave 48mm pistons).

H2OSB

[Piledriver]

Watch your brake bias, might want to run various combinations through the free calculator at https://brakepower.com.

The "default" rear caliper with parking brake is the Mk4 setup which from memory has a single floating 38mm piston, which effectively makes it two 38mm pistons as it's a double acting floater.
Try to score the aluminum version.

The tires will be the ultimate limiting factor in any case.

Note:If you plan on an adjustable rear bias/limiter valve, the rears should be almost same piston area as front, simply so you have something to turn down, at least on an ACVW. This is due to the extreme rear heavy weight bias.

If there was no weight transfer, you'd need much larger brakes on the back... If the CG gets low enough that becomes almost true.

On my square, 1G braking calls out between 54-58% front bias, depending on CG.
I went with 54% and ended up swapping 944T front calipers on the back for more area.
I do have slightly less grabby Mintex red pads out back, still have not felt a need to install the bias valve.

My setup is Wilwoods w/ 1.25"x4 pistons up front, and 2x40+2x36 (944T front) Brembos out back.
On a Bug the std rears 2x30 and 2x28 would probably work better as a T1 is taller.

Yes, my rear calipers are actually bigger area than my fronts, but the brake pads even things out.
Running PFC14 pads up front, Mintex red out back. The Pagids had too much grab out back.

[H2OSB]

Pile, as always, you offer great advice. I really hadn't wanted to run an adjustable proportioning valve, but am now reconsidering. They aren't very expensive, all things considered so I will likely have one in the end.

My entire brake plan is based around sound engineering, in that an aircooled VW had an almost identical weight distribution to the SWB 911s. They had 48mm front piston calipers and 38mm rear. Thus, when I had planned to use 944 brakes, I had the stock size 36mm rears (single pistons...but act the same a dual opposed pistons) and I exchanged the 54mm piston 944 singles for 911 M calipers with 48mm dual pistons (believe it or not, the M calipers bolt on in place of the 944 calipers, AND are centered over the 944 rotor).

However, now that I've decided I will go back 1303 spindles to re-acquire the factory geometry (alas, I'm still lowering the car, so......), I have to rethink a few things.

I will not consider using the typical disc brake conversions offered by many because I've already determined I want a bit more braking than those kits provide. The conversion kits come with 40mm piston Ghia calipers. I'd like to stick with the 911 formula of 48f/38r. The Wilwood calipers I choose are close to the Porsche sizes, albeit in inches. Also, I would like to go with solid rotors for the small weight savings they provide. I do not believe vented rotors are necessary for the "modest" maximum power I could end up with.

I could have custom hubs made, either from scratch or from modded 944 hubs (or turned down and re-drilled Beetle brake drums). There is also the possibility of repurposing the hub portion the the newish hub/rotors being produced by Cbperformance. I had a chance to get a good look at them at the most recent Sacramento Bug-O-Rama, and I'm pretty sure a set of SWB 911/912 solid front rotors, as well as any of later 911 rotors that bolt to the back side of the hub could be redrilled to work with those hubs.

That said, I have a brand new set of 914 front rotors from an earlier brake upgrade attempt on my son's 1303 that will work fine for my needs. Most don't know, but I've confirmed personally, 914 rotors as well as those from a 924 fit directly on a Super Beetle spindle without even changing to different bearings.

As an aside, if a person was ok with the 4x108 bolt pattern, 924 front rotors could be used in a brake upgrade with a matching rear brake conversion made by turning a 924 rear drum down into a hub for some 4 lug Audi rear rotor and Golf/Passat calipers with a custom adapter, although that's along the lines of reinventing the wheel. There are a couple of really cool 4 lug Audi wheel choices the should fit under a Beetle fender, and would make an interesting twist on German Look concept. Be aware, however, it is impossible to redrill a 4x108 bolt pattern to 5x130 without many partial hole overlaps, so 924 rotors can not be used to get the Porsche PCD.

I could go on forever.
H2OSB

[Piledriver]

Do note the "SWB" part of the early 911s, your beetle is significantly longer wheelbase, and that matters...
(run it through the calculator to see how much)

Yes, the 914/4 and even T3 rotors are for std BJ spindles, T3 lates are same as early 914, early T3 same as Ghia.
(or perhaps it was the other way around)
LATE 914/4 rotors are same as late, or all(?) 411/412s. (deeper offset)

The rotor offset varies by vary by year/application though.
If you are welding on a caliper mount, get whatever is easy to find.

Do consider the hubcentric size, as well as rotor centering if using a composite rotor (Any 2 piece)

The late VW hubcentric size was IIRC 83mm, those can be easily turned down to Porsche 73.ish mm, although you could fairly easily make up some "hubcentric" dust caps (with internal oring seal) for the more common non-hubcentric rotors.
Plastic hub adapter rings seem to be aviailable in almost any std size to ~anything larger.
If you run hubcentric spacers, the 944 front dust caps may fit those, so you may be able to skip the VW dust cap entirely.
(although you may need to drill a square hole for the speedo drive)

Don't rely on the bolts/studs for wheel centering, it makes a noticeable difference front and rear.
I even turned my rear T3 hubs to take a press-on aluminum hubcentric ring.
(the 944T stuff was already hubcentric and rotor-centering, so needed no mods when I went there)

Also note that CB sells 914 rear rotors in a 5x130 pattern, effectively rear 914/6 replacements.
On an actual 914 they center on the hub internally IIRC.

[Jadewombat]

I would stay away from 914 rear brakes. I adapted them on my friend's '69 ghia some 15+ years ago and we were very scientific about doing some braking distance testing before and after the swap from 60mph and the rear disks DID improve braking by reducing it a distance of 10ft., however the amount of work involved to grind down T3 hubs, weld up brackets, fit those little 914 calipers, and by today's standards with the allen key adjustment "centering" you need to do of the pads/calipers--it's a pretty hokey setup.

I did 924T brakes all around on my '73 1303. These brakes were phenomenal! I had welded in some plates on the front lower control arms to accept a Golf ball-joint and used a CNC drop-down pedal cluster with a balance-bar (individual MCs) because I didn't like "limiting" effect of a proportioning valve. That car was stripped down and the bias wound up being near 50-50 F-R. On a rabbit GTI, yeah it's probably 80-20 F-R. On my bug, no. I had a slightly more than stock engine in that car and drove the piss out of it in autoX. The pedal felt as solid as a Mercedes. The ONLY thing I didn't like is even as much bite as those tiny rear shoes had inside those rear rotors--a set of 30+ year old parking brakes from a 924T/944 make a weird sound and move a hair when you engage it (it's a semi-common problem).

I never tried it, but I like the idea of a set of 924 brakes adapted to a 1303. Easy, no ball joint adapting needing at the front and the rears bolt-up as easy as pie.

You said your on a budget H2O. Honestly, a set of decent used 924 or 944 brakes is worth well more than the new knockoff stuff sold. Those huge vented 944 rotors and calipers are nice to have, are they needed on a bug even with an engine 2X stock...hmm, debatable, but probably not. You can get away with a nice set of 924 stuff and have slots cut in the rotors and have a world of selection of cheap, very lightweight 14" 924 and Audi rims at your disposal.

[Piledriver]

You should probably decide on wheels before buying absolutely anything else.
Also agree the 924 brakes should be about free and work well, at least for the front.
(if you like the wheel/tire choices, decent 14" tires are like finding hens teeth these days)

5x112 might be a better choice...

Agree on not using the 914 calipers, they suck when they work right.
(venting clearance is set manually and is critical, and needs reset periodically if you want useful rear brakes, 914 rear calipers are not self adjusting, I think the new engineer got that task, along with the 914 trip odometer....)

OTOH with the MK4 rear 38mm calipers, they are pretty stout, and the parking brake action is very strong.
Also self adjusting if you use the parking brake as a good German should. (at every stoplight)

On a lowered bug, the 40mm Ghia fronts are probably a very good match to the 38mm Mk4 rears.
Might need a proportioning valve, I didn't but I was running larger BMW 2002Ti (40mmx4) fronts.
BTW, they might bolt on, and work well on a Bug.
They were a little too much for my T3 with the Mk4 rears, but a bug is taller.

I scored a nice set of staggered Forged Fuch (manholes) in 16x6/16X8 with the right offsets for $200.
16s seem a bit iffy for great AX tires though, limited sizes....
But they look and fit great on a T3. I really need to break down and have them polished.

The only downside is they completely hide the brakes.
I'm fine with that, makes it less obvious. (the 245s out back kinda ruin the stealth effect tho)

Note than any 924>968 had a 50/50 weight distribution so needed much more front bias.
Same was true for a SWB 911, not from weigh bias but due to the short wheelbase.

[H2OSB]

I will say, Steve Carter, with his first AeroLook early Super Beetle had late T3/T4 brakes with their 42mm pistons over 914 rotors on the front along with typical 944 rears with 36mm pistons over vented rotors and said they stopped great and were well balanced.

I don't know what to do. I want do it once and right. Light and effective...and relatively cheap. But then, don't we all.

I originally wanted to use the late 914 rotors due to their hubcentricity, but the offset was greater than the early rotors and I was trying to make them work on 924 spindles (making caliper brackets ended up being too difficult because 924 rotors are FAR smaller than 914 rotors thus the "ears" are closer to the spindle so the deeper offset wouldn't have mattered anyway...if that makes sense). The long and short of it is I have a pair of non-hubcentric rotors that I can re-drill and I'm too cheap to not use them.

I do like the some of the Audi wheels, particularly the "Sport" wheels that came on the Audi 90 verts, but I'm already committed to 5x130.

H2OSB

[Piledriver]

The area for a pair of 42mm calipers (2 calipers, total of 4 pistons or 2 floaters) is 8.58 sq cm.
In a 4 piston caliper, that slots the area in between 4x1.12" and 4x1.25"

2x48s are effectively just a tad smaller piston area than 4x1.380s

Unfortunately the piston size selection of Wilwoods Dynalites and other small calipers is not great, but a few offer 1.25" pistons.

914 front calipers would work well, but they also make great door stops. (heavy)

[raygreenwood]

Use the late 412 rotor. It was the same as late 914 rotor.
It goes like this:
VW 411 rotor fits VW 411 from 1968 to August of 1972. It also fits the 914 to August of 1972. It also fits the VW type 3 FROM 1971 onward to the end of production.

The 412 rotor FROM August of 1972 also fits 914 FROM August of 1972. This is the LATE rotor with the wider caliper, thicker brake pad and deeper hat/dish as mentioned.

The reason for this UPGRADE....really has nothing to do with caliper or pad thickness upgrades. Thats just a nice by product.

The EARLY rotor is inferior to the LATE rotor. You will notice that the late rotor has a "hub-centric" cuff around the spindle nut cap. This is to strengthen the rotor because the earlier rotor FLEXED heavily in cornering on cars with wider tires and more weight.

To combat the misalignment and piston/seal wear issues the early caliper had...the type 3 and type 4 cars had the caliper with the guide pin and clutch inside of the piston.

I would not base what you are doing around the earlier rotor. Ray

[Piledriver]

I can confirm early 914/411 rotor is used on the late T3s, late offset was too deep, hit the spindle backing plate.
It would probably do the same on a T1.
The late 914 spindle was a little longer. (still BJ)

I had a new set of late 914 rotors, didn't fit the late T3.
They fit my 74 914 fine of course.

I used a worn pair of late 914 factory rotors for my front hubs tho, with hats, plasma cut down and drilled and studded 5x130.
Sadly I had to cut down the hubcentric bit to 71.5mm(?) for the Porsche hubcentric size, so it lost some stiffness, didn't know about that tidbit, might have done it different.

The CB 6061T6 aluminum hubs with bolt on rotors are probably the best fix, and you are not stuck with the rotors or std offset if the backside is plain as reported.(save for the reported 5 x 4.25" pattern CB uses for their rotors with the funky cast in cutouts) I just wish we had some photos...
These are the "early" offset to match T1/T3 and Ghia, and from CBs pics and the description of the backside, its a pretty solid hunk of aluminum... They are not hubcentric tho, I would turn up some thick alloy dustcaps to fix that.
The price has gone up on these?...
http://www.cbperformance.com/product-p/4182.htm

I'd be curious if their plain $20 "wide 5 replacement rotor" would fit those, drilled and slotted makes for cracked rotors in hard use, although they look great. (I don't dare harass Maryanne any more than I have)

Wilwood has a variety of hat mounts for backside hub attachment, and as its just a circle of aluminum or steel custom would be relatively cheap to mount ~any bolt on rotor out there.

I'm still eyeing these 2" thick 5x130<>5x130 spacers and 914 rear wheel bearings... to become hubs.
Just need a hunk of CrMo tube the right ID/OD to become an axle... That and a pair of T1 flywheel bolts to hold them on.(and the tap to match)

Porsche uses those or very similar dual row sealed bearings on all 4 corners of everything they make from the 90s to date.

[burls]

Has anyone put Subaru brakes all round and had success

[davidt]

Here is what I have fitted to my 1302. I picked up a set of VW Passat Borbett 10 spoke alloys in 16x7in size with a 45mm offset and these will look great painted white and should fit under the factory guards. But these rims have a different stud pattern of 5x112PCD instead of the original Beetle 4x130PCD. Blank front discs and drums would be needed at a minimum. So I will carry out a big brake conversion at the same time. My conversion is as follows: Front Brakes - Blank standard front discs machined down to a hub assembly with a hub-eccentric adapter and drilled for 5x112mm PCD. Custom 12mm thick caliper mounting brackets. Rebuilt Volvo 240 front 4-pot calipers with 38mm pistons (from a 1270-1465kg curb weight car). REMSA 660 degree C pads and Mercedes Benz Vito ventilated front 276x22mm discs (from a 1970kg curb weight car). Standard VW front disc brake package weighs 9kg. Upgraded ventilated front disc brake package weighs 13kg. Rear Brakes - 280x10mm solid blank VW aftermarket disc assembly with a hub-eccentric adapter and drilled for 5x112mm PCD. SparpBuilt (from Toowoomba, QLD) alloy caliper brackets. Suzuki SX4 rear calipers with 34mm pistons and cable operated handbrake (from a 1170-1245kg curb weight car). Both of the vehicles that supplied the calipers use 22.2mm master cylinders. So I used a 68-69 Bay window 22.2mm L/H drive master cylinder (211611021Q) which has the brake line outlets on the correct side of the master cylinder for fitment into a RHD Beetle. I had to lengthen the push-rod to suit, plus I blanked off one front outlet and removed the 10psi check valves from the other two outlets as this master cylinder was originally for a dual-drum-brakes application. I removed the clutch/brake/throttle pedal assemblies and cut off the brake push-rod plate and then welded on a longer custom version with the push-rod pivot higher up. This improved the brake pedal ratio from 6.6:1 to 4.4:1 which reduces the pedal travel considerably. Then the brakes were bled with Nulon high temp fluid. My 16x7in Borbett alloys (painted white with temporary 205/60R16 tyres) were fitted and I went for my first drive for close on eight months. The brake pads required bedding-in so off to a quiet stretch of road we went. These brakes feel really good. The pedal only moves about an inch where it then goes firm. This gives good soft braking control. Under hard braking, pedal modulation is also quite easy and very controllable. No problem with front to rear brake balance or lock-ups. The extra grip from the front tyres is a real bonus too. So far I am more than happy with the outcome. P.S. – If anyone wants a set of Volvo caliper mounting plates or brake pedal master cylinder pivot plate, then please let me know.

[H2OSB]

Here is what I have fitted to my 1302. I picked up a set of VW Passat Borbett 10 spoke alloys in 16x7in size with a 45mm offset and these will look great painted white and should fit under the factory guards. But these rims have a different stud pattern of 5x112PCD instead of the original Beetle 4x130PCD. Blank front discs and drums would be needed at a minimum. So I will carry out a big brake conversion at the same time. My conversion is as follows: Front Brakes - Blank standard front discs machined down to a hub assembly with a hub-eccentric adapter and drilled for 5x112mm PCD. Custom 12mm thick caliper mounting brackets. Rebuilt Volvo 240 front 4-pot calipers with 38mm pistons (from a 1270-1465kg curb weight car). REMSA 660 degree C pads and Mercedes Benz Vito ventilated front 276x22mm discs (from a 1970kg curb weight car). Standard VW front disc brake package weighs 9kg. Upgraded ventilated front disc brake package weighs 13kg. Rear Brakes - 280x10mm solid blank VW aftermarket disc assembly with a hub-eccentric adapter and drilled for 5x112mm PCD. SparpBuilt (from Toowoomba, QLD) alloy caliper brackets. Suzuki SX4 rear calipers with 34mm pistons and cable operated handbrake (from a 1170-1245kg curb weight car). Both of the vehicles that supplied the calipers use 22.2mm master cylinders. So I used a 68-69 Bay window 22.2mm L/H drive master cylinder (211611021Q) which has the brake line outlets on the correct side of the master cylinder for fitment into a RHD Beetle. I had to lengthen the push-rod to suit, plus I blanked off one front outlet and removed the 10psi check valves from the other two outlets as this master cylinder was originally for a dual-drum-brakes application. I removed the clutch/brake/throttle pedal assemblies and cut off the brake push-rod plate and then welded on a longer custom version with the push-rod pivot higher up. This improved the brake pedal ratio from 6.6:1 to 4.4:1 which reduces the pedal travel considerably. Then the brakes were bled with Nulon high temp fluid. My 16x7in Borbett alloys (painted white with temporary 205/60R16 tyres) were fitted and I went for my first drive for close on eight months. The brake pads required bedding-in so off to a quiet stretch of road we went. These brakes feel really good. The pedal only moves about an inch where it then goes firm. This gives good soft braking control. Under hard braking, pedal modulation is also quite easy and very controllable. No problem with front to rear brake balance or lock-ups. The extra grip from the front tyres is a real bonus too. So far I am more than happy with the outcome. P.S. – If anyone wants a set of Volvo caliper mounting plates or brake pedal master cylinder pivot plate, then please let me know.

Neat set up.

I've changed my mind substantially since I started this thread. On the rear I have standard Porsche 944 brakes from an '85 NA car. I had to use extended tubes and "swans" to allow the use of a factory parking brake cable.
The front is mostly 944 with the exception of a turned down rotor and hub to allow clearance for widened 914 calipers(they bolt directly to the 944 spindles, once the rotor AND hub were clearanced enough for everything to fit). The calipers are the early 914 variety. I used the spacers from mid 70s 911 REAR M calipers(rear M calipers are the exact same casting as 914 front calipers...but with a 35mm piston) to make the 914 calipers wide enough to fit over the 944 rotors. I needed a 1.5mm thick shim washer between the caliper and spindle at each bolt to have the caliper perfectly centered over the rotor.

Sadly, where I felt I spent too much money on this set up was the bolts to hold the caliper halves together. If one were careful, you could recycle the Ribe bolts from the rear M calipers that were sacrificed to get the spacers, however, my source calipers had damaged Ribe sockets as if someone had used the wrong tool to try to get them out. I had to drill out 5 of the 8 bolts between the two calipers. The Ribe bolts for those particular calipers(as well as 914 calipers) are non-standardized M7 bolts. They have not been produced for nearly 40 years. If replacements can be found, they are incredibly expensive and should be saved for those doing concourse type restorations(due to cost...I don't mean that in a hoity toity way). I found people online doing similar 914 caliper widening who redrilled to 3/8th SAE or M8. I just didn't feel it was safe. I opted to buy bolts from a company in Germany called Tola-Tools, which was the only company ANYWHERE who offered M7 socket head bolts in both the correct lengths and hardness(12.9). The bolts were incredibly expensive and cost nearly as much to ship them as the bolts themselves. If I were to do it again, I wouldn't go this route.

I really like my front brake set up, otherwise, with the exception of needing to reduce the diameter of the rotors. I have been thinking of a set up along the lines of the above quoted front set up. Whereby I would acquire 5x130 rotors for 1303 spindles, cut down to hubs with a spacer and a stock 944 rotor bolted to the back of the hub, then a bolt on adapter and caliper. CSP sells a rotor that is specially reinforced(i.e. thicker) to take any wheel bolt pattern. I think these would make an ideal hub.

H2OSB